1. Technical Subject
The innovation disclosed hereunder consists in a device for controlling at least one thread in a textile machine, especially a warp thread in a weaving loom.
2. State of the Art
Numerous devices for the controlling of the transverse movement of a thread in a textile machine, especially a warp thread are well known to those learned in the art. The threads are threaded through and guided by the eyes of heddles which are moved, according to a determined programme and via connecting structures, by different driving devices such as jacquard machines, heddle looms, treadle looms and colour control units. These machines and devices involve large numbers of different components, which unavoidably exerts a negative influence on the speed of the thread control mechanism. The already disclosed systems are additionally characterised by the following significant disadvantages: high forces of gravity, significant wear and tear, great emission of noise, significant vibration, enormous space requirements, high production and operating costs, poor ergonomic characteristics, etc.
So far, many attempts were made to eliminate these disadvantages.
Under U.S. Pat. No. 3,867,966, for example, a device of the type mentioned above was disclosed which attempts to eliminate the disadvantages described by way of introduction. This device comprises a dragging element inserted between two springs, which serves to drag at least one thread. An arresting device controlled by means of a control unit serves to temporarily arrest the dragging element in at least one extreme position. The dragging element is designed in the form of a heddle, which comprises a ribbon section, which contains a conductor and is located between two isolators. This ribbon section runs over a roller, which can be electrically activated. As soon as electrical current is fed to the roller or to the ribbon section, respectively, friction between the roller and the ribbon section increases so that the ribbon section can be dragged by the roller and moved to an extreme position where magnetic arresting devices are located which arrest the heddle as long as the electrical arresting devices are activated. A considerable disadvantage of this type of device, however, consists in the fact that the heddle must be equipped with a ribbon section, which contains electrically conducting elements and that dragging is effected by friction only. This causes high wear between the roller and the ribbon section. Additionally, even friction between the ribbon section and the roller cannot be guaranteed, because friction is constantly changing due to both wear and the accumulation of dirt.